I saw the tail end of this movie several years ago. I think it was set in the 1970s. The end was of a man who was searching for his daughter who was kidnapped by her mother who is a witch. It wasn't a documentary, but did have a "based on actual events" feel to it. I don't know who the actor was, but I remember there was voice over about never having found his daughter. I've googled every possible way I can think of and I can't find it.